The use of a drum cam on a shaft for driving a printing carriage back and forth across a printer requires that the drive member for the drum cam be precisely secured or fastened on the shaft. Various ways and means for fastening drive or like members have included key ways and keys, set screws, roll pins, and mating surfaces such as splined or flatted shafts.
Additionally, it is also desirable to provide for selective positioning of the drive member on the shaft so as to enable the shaft with its associated devices to be used in more than one application. In this regard, the drive member is movable along the shaft and secured at one of a plurality of positions on the shaft.
Representative prior art includes U.S. Pat. No. 1,030,592, issued to J. A. Leland on June 25, 1912, which shows a telescopic extension rod with a longitudinal groove and recesses in the groove. A tube slides on the rod and has a clutch lever with projections and an adjustable sleeve.
U.S. Pat. No. 2,131,152, issued to B. C. Stickney on Sept. 27, 1938, shows a typewriter shaft having an impaling-pin wheel at each end and moved into and out of position by a control lever.
U.S. Pat. No. 2,360,196, issued to C. W. Brumhill on Oct. 10, 1944 discloses a platen carriage in a typewriter with releasable latching mechanism for holding a tear-off knife in the operative position and means for retaining the knife in an inoperative position.
U.S. Pat. No. 2,411,293, issued to W. A. Roehner on Nov. 19, 1946, shows a ticket roll on a hub and a resilient element bearing against one side of the roll for a stopping or braking effect thereof.
U.S. Pat. No. 2,963,138 issued to W. S. Motte et al on Dec. 6, 1960 shows an accounting machine with a shiftable platen and a plurality of pressure rollers.
U.S. Pat. No. 3,047,318 issued to R. H. Berkshire on July 31, 1962 shows a device for precision mounting of a gear on a shaft which utilizes a hole defined along the shaft, a radial bore in the hub, a tapered plug for press-fitting in the radial bore and a pin wedged for a press-fit with the plug and the pin cooperating to provide axial adjustment on the shaft by rotation of the tapered plug.
U.S. Pat. No. 3,245,633 issued to A. Madel on Apr. 12, 1966, shows a cash register with a paper tensioning member and drag means for maintaining and releasing the member.
U.S. Pat. No. 3,362,738 issued to G. C. Dygert et al on Jan. 9, 1968, shows a fitting to secure a support to a frame with the fitting having a base and legs with openings for a straight bar. A pin is biased by a spring through an opening in the bar and secures the support in a desired opening in the frame member.
U.S. Pat. No. 3,426,880 issued to E. O. Blodgett on Feb. 11, 1969, shows a matrix page printer with a guide rail and teeth engaged by a pawl nose section for adjusting along the guide rail.
U.S. Pat. No. 3,525,271 issued to M. H. Raines on Aug. 25, 1970, shows a gear with a spring pressed key in a beveled key way formed on a shaft to remove a gear when the shaft is rotating or when it is stationary.
U.S. Pat. No. 3,612,582 issued to A. Pitner of Oct. 12, 1971, shows mounting of a member on a shaft wherein two U-joint yokes are each provided with a hub, and a dowel pin or key is used both to secure the yoke on the shaft and to fix the two yokes in driving relation. A pin or key may also be used to press into the shaft to form the shaft with a seat for the pin.
U.S. Pat. No. 3,655,023 issued to A. Stanevich on Apr. 11, 1972, shows a platen assembly for a typewriter with selective disengagement of a first clutch through a second clutch and several means of platen rotation by use of the clutches in single manner or in engaged manner.
U.S. Pat. No. 3,753,483 issued to I. H. Lundquist et al. on Aug. 21, 1973, shows a typewriter dual feed apparatus with a single arm and linkage assembly for roller release feed in a first position and for retraction of the platen for computer feed in a second position.
U.S. Pat. No. 3,830,577 issued to John W. Rampe et al. on Aug. 20, 1974, shows a shaft and a hub with an aperture positioned to receive a pin and whereby the pin is forced into the shaft by crimping the sides of a clamp.
And, U.S. Pat. No. 3,915,281 issued to J. E. Blomquist et al. on Oct. 28, 1975, shows paper feed mechanism for a printer with a shaft with spaced peripheral grooves selectively engageable by a flexible in-turned flange on the end of a sleeve which is rotatably mounted on the shaft.